Strongly seconding the suggestion of physiotherapy. It could very easily be soft tissue (surely they will have taken x-rays to confirm bone healing?), but that doesn't mean it will necessarily get better by itself. She needs to re-learn how to use the leg properly, and physio is the best way to do that. However, just going to the physiotherapist is not enough. What the physio does is great, but will only be fully effective if she also DOES THE EXERCISES THE PHYSIO GIVES HER.

I did my exercises, even when it was 20 reps of each of 6-10 exercises four times a day. Yes, it was sometimes boring, and I didn't always want to take the time needed. But I'm back to running ultramarathons...